This part of EN 12201 gives guidance for the assessment of conformity of compounds, products, joints and assemblies in accordance with the applicable part(s) of EN 12201 intended to be included in the manufacturer’s quality plan as part of the quality management system and for the establishment of certification procedures. It is recommended that the quality management system conforms to or is no less stringent than the relevant requirements to EN ISO 9001 [1]. NOTE 1 If certification is involved, the certification and inspection body is preferably compliant with EN ISO/IEC 17065 [5], EN ISO/IEC 17021 [3] or EN ISO/IEC 17020 [2], as applicable. In conjunction with Parts 1 to 5 of EN 12201 (see Foreword) this document is applicable to polyethylene (PE) plastics piping systems for water supply, and for drainage and sewerage under pressure. It is applicable to PE pipes, fittings, and valves, their joints and to joints with components of other materials intended to be used under the following conditions: a) allowable operating pressure, PFA, up to 25 bar1); b) an operating temperature of 20 °C as a reference temperature; c) buried in the ground; d) sea outfalls; e) laid in water; f) above ground, including pipes suspended below bridges. NOTE 2 For applications operating at constant temperature greater than 20 °C and up to 40 °C, see EN 12201-1:2011, Annex A. NOTE 3 It is the responsibility of the purchaser or specifier to make the appropriate selections from these aspects, taking into account their particular requirements and any relevant national guidance or regulations and installation practices or codes.